The long-range goal of this research proposal is to understand the assembly and dynamics of an essential eukarydtic organelle, the mitochondrion. The assembly of mitochondria is dependent upon the import of proteins from the cytosol, a process that utilizes complicated machinery in both the mitochondrial inner and outer membranes. Although much of the import apparatus has been identified, additional import components await identification. In addition, many unanswered question remain about the mechanism by which preproteins are translocated across the mitochondrial membranes, or inserted into the hydrophobic environment of the lipid bilayer. ? ? Mitochondria are also dynamic organelles, continuously fusing, dividing and moving within cells by processes under exquisite control. Mitochondria also show a wide variety of shapes and numbers in different cell types. Although the dynamic nature of mitochondria has been documented for over TOO years, little is known about the molecules or mechanisms mediating the fusion, division, segregation and shape of the organelle. ? ? To further our understanding of mitochondrial assembly and dynamics, we have isolated mutants in the yeast, Saccharomyces cerevisiae, that are defective in mitochondrial function. We propose to continue our analyses of mitochondrial proteins identified by our genetic stusies, and will focus on the following questions: ? ? 1) How is mitochondrial shape established and mtDNA maintained? ? 2) What is the mechanism of mitochondrial protein import, and how is it related tomitochondrial shape? ? 3) What is the mechanism of mitochondrial division? ? 4) What is the mechanism of mitochondrial fusion? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM054021-12
Application #
7487533
Study Section
Cell Structure and Function (CSF)
Program Officer
Deatherage, James F
Project Start
1996-06-01
Project End
2010-08-31
Budget Start
2008-09-01
Budget End
2010-08-31
Support Year
12
Fiscal Year
2008
Total Cost
$418,698
Indirect Cost
Name
Johns Hopkins University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Clayton, April M; Guler, Jennifer L; Povelones, Megan L et al. (2011) Depletion of mitochondrial acyl carrier protein in bloodstream-form Trypanosoma brucei causes a kinetoplast segregation defect. Eukaryot Cell 10:286-92
Yamamoto, Hayashi; Itoh, Nobuka; Kawano, Shin et al. (2011) Dual role of the receptor Tom20 in specificity and efficiency of protein import into mitochondria. Proc Natl Acad Sci U S A 108:91-6
Roy Chowdhury, Arnab; Bakshi, Rahul; Wang, Jianyang et al. (2010) The killing of African trypanosomes by ethidium bromide. PLoS Pathog 6:e1001226
Jensen, Robert E; Simpson, Larry; Englund, Paul T (2008) What happens when Trypanosoma brucei leaves Africa. Trends Parasitol 24:428-31
Dunn, Cory D; Tamura, Yasushi; Sesaki, Hiromi et al. (2008) Mgr3p and Mgr1p are adaptors for the mitochondrial i-AAA protease complex. Mol Biol Cell 19:5387-97
Cerveny, Kara L; Studer, Seth L; Jensen, Robert E et al. (2007) Yeast mitochondrial division and distribution require the cortical num1 protein. Dev Cell 12:363-75
Davis, Alison J; Alder, Nathan N; Jensen, Robert E et al. (2007) The Tim9p/10p and Tim8p/13p complexes bind to specific sites on Tim23p during mitochondrial protein import. Mol Biol Cell 18:475-86
Sesaki, Hiromi; Jensen, Robert E (2004) Ugo1p links the Fzo1p and Mgm1p GTPases for mitochondrial fusion. J Biol Chem 279:28298-303
Youngman, Matthew J; Hobbs, Alyson E Aiken; Burgess, Shawn M et al. (2004) Mmm2p, a mitochondrial outer membrane protein required for yeast mitochondrial shape and maintenance of mtDNA nucleoids. J Cell Biol 164:677-88
Sesaki, Hiromi; Southard, Sheryl M; Yaffe, Michael P et al. (2003) Mgm1p, a dynamin-related GTPase, is essential for fusion of the mitochondrial outer membrane. Mol Biol Cell 14:2342-56

Showing the most recent 10 out of 16 publications